Phenology and behavior of Chauliognathus marginatus (Fabr.) (Coleoptera: Cantharidae) in Virginia agroecosystems

Chauliognathus marginatus (Fabr.) is a frequent visitor of weeds, wildflowers, and disturbed areas in and around agricultural areas throughout eastern North America. Because of this beetle's pollination and biological pest management potential, it is important to understand its seasonal activity and behavior to maintain any benefits it provides and protect it from unintentional exposure to pest control methods. We studied the phenology of C. marginatus for two years (2018-2019) and found that adult beetles are active on a variety of flowers from mid-May to late July. On these flowers, they spent a large percentage of their day mating or feeding, with significant differences in the percentage of beetles participating in behaviors based on time of day and beetle sex. The majority of C. marginatus observations occurred on narrowleaf mountain mint (Pycnanthemum tenuifolium Schrad.), poison hemlock (Conium maculatum L.), and wild bergamot (Monarda fistulosa L.). To our knowledge, this is the first study to characterize the phenology or behavior of this common and conspicuous beetle species.